© 2015, SatService GmbH www.satnms.com ACU-STEP-1512-1 1/2

sat-nms Antenna Step Track System The sat-nms ACU adaptive step-track system is an antenna manufacturer independent tracking system that can be

easily connected to any satellite ground station antenna. The two core modules are:

• sat-nms ACU-ODM Tracking System

• sat-nms LBRX Beacon Receiver

The modular architecture and standard

interfaces simplify a new or a retrofit

integration. The sat-nms ACU Antenna

Control System is an economic alternative

to the systems provided by other antenna

manufacturers. SatService GmbH provides

upgrade kits for all antenna types found

on the market and can also perform on-

site system integration.

The sat-nms ACU-ODM Outdoor Module is

the core module of a complete antenna

step-track system, which tracks precisely

any antenna size on the satellite. The software does not only implement the standard step tracking mode but

SatService has also implemented an improved adaptive tracking algorithm. The sat-nms ACU records the tracked

positions over several days and calculates based on this data a mathematical model that is used to predict the

antenna position. This reduces the step-track failure and provides continuous operation in case of a beacon

receive failure.

In the Program Tracking Mode, the antenna follows a path defined by a file containing time stamped azimuth,

elevation and polarization values. They have usually have been calculated by an external software.

The DIN Rail Module provides all necessary interfaces to any antenna.

Therefore, the sat-nms ACU-ODM can be very flexible adapted to any

type of antenna as the motor controllers can be selected

independently.

• Three motor controllers, like DC servos (for smaller antennas or

frequency inverters, commonly used in larger antennas

• Limit switches, Interlock and Motor-Off Switches

• Angular detectors measuring azimuth, elevation and polarization

angle, three different daughter boards are available covering most

of the different angle detectors used in satellite ground stations:

o Analog resolver, covering the existing antennas

o Digital angle detectors with SSI interface

o A/D interface to measure the voltage across a precision

potentiometer

The DIN Rail Module is normally integrated in the sat-nms ACU-ODU

cabinet at the antenna mount, together with the sat-nms LBRX

Beacon Receiver (also available as DIN Rail Module).

Contact Information

SatService

Gesellschaft für Kommunikationssysteme mbH

Hardstrasse 9, D-78256 Steisslingen, Germany

Phone +49 7738 99791 10,

Fax +49 7738 99791 99

E-Mail sales@satservicegmbh.de

www.satnms.com, www.satservicegmbh.de

Key Features

• Adaptive Step-Tracking with self-learning Orbit Model

Tracking Algorithm

• Together with sat-nms LBRX a complete step- track

System in Cabinet at the Antenna

• Web-based, user-friendly Operator Interface

• HTTP Protocol for external MNC Interface

• High sophisticated sat-nms ACU-IDU Indoor Unit

© 2015, SatService GmbH www.satnms.com ACU-STEP-1512-1 2/2

The sat-nms ACU-ODM Module includes an integrated web server and provides its operator interface via web

browser. The Ethernet is the main interface and the sat-nms ACU-ODM Processor includes http, ftp and telnet

services for remote diagnosis and support. The system is easy to maintain and all support can be performed

remotely. Furthermore, the interface to high-level Monitoring and Control Systems or a sat-nms ACU-IDU is

provided via Ethernet and TCP/IP.

Technical Specification Positioning / Tracking

Position Encoding Resolver, Digital SSI and Potentiometer, scalable per Axis

Quantization Error Resolver 16bit: 0.0055°

SSI: 13bit: 0.044°, 16bit: 0.0055°, 17bit: 0.0028°, 19bit: 0.0007°

Display Position Resolution 0.001°

Maximum travel rate of each antenna axis 1°/sec

Interfaces to Beacon Receivers sat-nms LBRX or analog Voltage Input for other Vendors Equipment

Analog Voltage Input 0 to 10V

Option Tracking Accuracy Encoder Coupling and Alignment Error should not exceed 0.003° to achieve

specified Tracking Accuracy. The Influence of Antenna Structure Thermal Error is

not considered.

In step-track Mode Better than 10% of Receive 3dB Beamwidth (RMS).

In adaptive tracking Mode Better than 5% of Receive 3dB Beamwidth (RMS).

Position Encoding 1 LSB of Resolver / Digital Conversion

Operational Modes Manuel Mode, Step Track, Adaptive Tracking takes into account last Days History,

Program Tracking based on time stamped File Data

Number of Presets 99 Storage of sat-nms ACU Configuration (including sat-nms LBRX Beacon

Receiver Settings)

System Interfaces

sat-nms MNC Interface 10-Base-T, via HTTP GET Requests

Operator Access With Web Browser

To sat-nms MNC and sat-nms ACU-IDU Ethernet RJ45 or RS232

To 6 Limit Switches Opto-Coupler Input for Azimuth, Elevation and Polarization

Interlock and Motors-off switches Opto-Coupler Input

3 Angular Detectors Resolver, SSI or A/D Input

Motor Driver Interface

(For Frequency Inverter, DC servos etc.)

Via Opto-Coupler In- and Outputs: Motor on/off and Direction, low and high

Speed Selection, Reset Driver, Driver Fault

Electrical and Mechanical Specification, Environmental Conditions

Supply Voltage Any Type of 230V

AC Mains Voltage

Single or 3-phase

Temperature Range 5° to 50° C

Humidity Up to 90% non-condensing

Outdoor Cabinet Size

(with Rain Canopy)

610 x 795 x 235 mm

(WxHxD)

ACU Indoor Unit

The sat-nms ACU-IDU is for customers who want to

have a more classic antenna step-track system, which

also provides an Indoor Unit. This sat-nms ACU

System does provide even more functionality, like

data archiving, adaptive tracking, tracking on the

basis of Intelsat data, two-line Kepler elements,

graphical presentation of the angular and beacon

level variation via time and other sophisticated

features. The sat-nms ACU-IDU is an industrial PC

incorporating digital technology for accurate antenna

tracking with high reliability, flexibility and a user-

friendly operator interface. This system is ideally

uited for all kind of satellite ground station antennas.